It is very similar to running gpg-agent in server mode; but here we connect to a running instance.

The following options may be used:

-v

--verbose

Output additional information while running.

-q

--quiet

Try to be as quiet as possible.

--homedir dir

Set the name of the home directory to dir. If his option is not used, the home directory defaults to `~/.gnupg'. It is only recognized when given on the command line. It also overrides any home directory stated through the environment variable `GNUPGHOME' or (on W32 systems) by means on the Registry entry HKCU\Software\GNU\GnuPG:HomeDir.

-S

--raw-socket name

Connect to socket name assuming this is an Assuan style server. Do not run any special initializations or environment checks. This may be used to directly connect to any Assuan style socket server.

-E

--exec

Take the rest of the command line as a program and it's arguments and execute it as an assuan server. Here is how you would run gpgsm:

 gpg-connect-agent --exec gpgsm --server

--no-ext-connect

When using -S or --exec, gpg-connect-agent connects to the assuan server in extended mode to allow descriptor passing. This option makes it use the old mode.

While reading Assuan commands, gpg-agent also allows a few special commands to control its operation. These control commands all start with a slash (/).

/echo args

Just print args.

/definqfile name file

Use content of file for inquiries with name. name may be an asterisk (* to match any inquiry.

/definqprog name prog

Run prog for inquiries matching name and pass the entire line to it as command line arguments

/showdef

Print all definitions

/cleardef

Delete all definitions

/sendfd file mode

Open file in mode (which needs to be a valid fopen mode string) and send the file descriptor to the server. This is usually followed by a command like INPUT FD to set the input source for other commands.

/recvfd

Not yet implemented.

/help

Print a list of available control commands.

The full documentation for this tool is maintained as a Texinfo manual. If GnuPG and the info program are properly installed at your site, the command

info gnupg

should give you access to the complete manual including a menu structure and an index.